Alzhemer's disease is the most common cause of both presenile and senile dementia. A genetic component appears to be involved since there is an increased risk among first order relatives of affected individuals. Unfortunately, these at risk individuals cannot be diagnosed prior to the onset of the early dementium symptoms. We propose to use molecular cloning techniques to determine if cells from Alzheimer individuals contain one or more unique "Alzheimer-specific" transcripts or mRNAs. If such transcripts exist and can be identified, we propose to check for their presence in cells obtained from at risk individuals. Identification of one or more mRNAs present only in cells obtained from individuals with Alzheimer's disease or at risk individuals and not found in presumptive normal, age and sex matched controls would suggest that a molecular analysis such as this could serve as a pre or early symptomatic diagnostic test.